Query Monitor


Query Monitor is the developer tools panel for WordPress. It enables debugging of database queries, PHP errors, hooks and actions, block editor blocks, enqueued scripts and stylesheets, HTTP API calls, and more.

It includes some advanced features such as debugging of Ajax calls, REST API calls, and user capability checks. It includes the ability to narrow down much of its output by plugin or theme, allowing you to quickly determine poorly performing plugins, themes, or functions.

Query Monitor focuses heavily on presenting its information in a useful manner, for example by showing aggregate database queries grouped by the plugins, themes, or functions that are responsible for them. It adds an admin toolbar menu showing an overview of the current page, with complete debugging information shown in panels once you select a menu item.

For complete information, please see the Query Monitor website.

Hier eine Übersicht, was für jeden Seitenaufruf angezeigt wird:

  • Database queries, including notifications for slow, duplicate, or erroneous queries. Allows filtering by query type (SELECT, UPDATE, DELETE, etc), responsible component (plugin, theme, WordPress core), and calling function, and provides separate aggregate views for each.
  • Der Template-Dateiname, die komplette Template-Hierarchie und die Namen aller Template-Komponenten, die geladen oder nicht geladen wurden.
  • PHP errors presented nicely along with their responsible component and call stack, and a visible warning in the admin toolbar.
  • Blocks and associated properties in post content when using WordPress 5.0+ or the Gutenberg plugin.
  • Angewandte Weiterleitungen (rewrite rules) sowie damit zusammenhängende Abfrage-Strings und Abfrage-Variablen.
  • Enqueued scripts and stylesheets, along with their dependencies, dependents, and alerts for broken dependencies.
  • Spracheinstellungen und geladene Übersetzungsdateien (.mo-Files) für jede Textdomain.
  • HTTP API requests, with response code, responsible component, and time taken, with alerts for failed or erroneous requests.
  • Prüfung der Benutzer-Berechtigungen; enthalten sind sowohl das Ergebnis als auch alle Parameter, die an die Prüfung übergeben wurden.
  • Infos zur Umgebung, inklusive detaillierter Informationen über PHP, Datenbank, WordPress und den Webserver
  • Die Werte aller konditionalen Funktionen von WordPress wie zum Beispiel is_single(), is_home(), etc.
  • Transienten, die aktualisiert wurden


  • Whenever a redirect occurs, Query Monitor adds an HTTP header containing the call stack, so you can use your favourite HTTP inspector or browser developer tools to trace what triggered the redirect.
  • The response from any jQuery-initiated Ajax request on the page will contain various debugging information in its headers. PHP errors also get output to the browser’s developer console.
  • The response from an authenticated WordPress REST API request will contain various debugging information in its headers, as long as the authenticated user has permission to view Query Monitor’s output.

In der Standardeinstellung sind die Ausgaben von Query Monitor nur sichtbar für Administratoren (in Einzel-Installationen) bzw. Super-Admins (in Multisite-Installationen).

In addition to this, you can set an authentication cookie which allows you to view Query Monitor output when you’re not logged in (or if you’re logged in as a non-Administrator). See the Settings panel for details.

Other Plugins

I maintain several other plugins for developers. Check them out:

  • User Switching provides instant switching between user accounts in WordPress.
  • WP Crontrol lets you view and control what’s happening in the WP-Cron system


Query Monitor is private by default and always will be. It does not persistently store any of the data that it collects. It does not send data to any third party, nor does it include any third party resources.

Die vollständige Datenschutzerklärung für Query Monitor findest du hier (engl.).


  • Admin Toolbar Menu
  • Zusammenfassen von Datenbank-Abfragen nach Komponenten
  • Prüfung der Berechtigungen
  • Datenbank-Abfragen
  • Hooks und Actions
  • HTTP API Requests
  • Aggregate Datenbank-Abfragen by Calling Function


Does this plugin work with PHP 8?


Who can access Query Monitor’s output?

In der Standardeinstellung sind die Ausgaben von Query Monitor nur sichtbar für Administratoren (in Einzel-Installationen) bzw. Super-Admins (in Multisite-Installationen).

In addition to this, you can set an authentication cookie which allows you to view Query Monitor output when you’re not logged in, or when you’re logged in as a user who cannot usually see Query Monitor’s output. See the Settings panel for details.

Beeinflusst Query Monitor die Zeit für die Erzeugung der Seite oder die Speicherauslastung?

Kurze Antwort: Ja, aber nur geringfügig.

Long answer: Query Monitor has a small impact on page generation time because it hooks into WordPress in the same way that other plugins do. The impact is low; typically between 10ms and 100ms depending on the complexity of your site.

Der typische Speicherbedarf für Query Monitor liegt bei ungefähr 10% des Speichers, der für die generierte Seite benötigt wird.

Are there any add-on plugins for Query Monitor?

Hier findest du eine Liste an Erweiterungen für Query Monitor

In addition, Query Monitor transparently supports add-ons for the Debug Bar plugin. If you have any Debug Bar add-ons installed, just deactivate Debug Bar and the add-ons will show up in Query Monitor’s menu.

Wo kann ich eine neue Funktion vorschlagen oder einen Fehler melden?

Please use the issue tracker on Query Monitor’s GitHub repo as it’s easier to keep track of issues there, rather than on the wordpress.org support forums.

Is Query Monitor available on Altis?

Yes, the Altis Developer Tools are built on top of Query Monitor.

Is Query Monitor available on WordPress.com VIP Go?

Yes, it’s included as part of the VIP Go platform. However, a user needs to be granted the view_query_monitor capability to see Query Monitor even if they’re an administrator.

I’m using multiple instances of `wpdb`. How do I get my additional instances to show up in Query Monitor?

You’ll need to hook into the qm/collect/db_objects filter and add an item to the array containing your wpdb instance. For example:

add_filter( 'qm/collect/db_objects', function( $objects ) {
    $objects['my_db'] = $GLOBALS['my_db'];
    return $objects;
} );

Your wpdb instance will then show up as a separate panel, and the query time and query count will show up separately in the admin toolbar menu. Aggregate information (queries by caller and component) will not be separated.

Can I click on stack traces to open the file in my editor?

Yes. You can enable this on the Settings panel.

Akzeptierst du Spenden?

I am accepting sponsorships via the GitHub Sponsors program and any support you can give will help me maintain this plugin and keep it free for everyone.

In addition, if you like the plugin then I’d love for you to leave a review. Tell all your friends about it too!


I would consider Query Monitor an essential tool for developers. It does SO much great stuff and has an awesome interface. The support is top-notch, and the developer has factored in MultiSite perfectly 😍
26. Februar 2021
Hi, I've discovered Query Monitor today searching for a tool around MySQL slow queries. I'm happy to find this very rich tool which provides so many informations. I'm sure, I will use it on development environments. Thank you for your work on this plugin.
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„Query Monitor“ wurde in 18 Sprachen übersetzt. Danke an die Übersetzerinnen und Übersetzer für ihre Mitwirkung.

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